Salts on Europa's surface detected by Galileo's near infrared mapping spectrometer. The NIMS Team.

Reflectance spectra in the 1- to 2.5-micrometer wavelength region of the surface of Europa obtained by Galileo's Near Infrared Mapping Spectrometer exhibit distorted water absorption bands that indicate the presence of hydrated minerals. The laboratory spectra of hydrated salt minerals such as magnesium sulfates and sodium carbonates and mixtures of these minerals provide a close match to the Europa spectra. The distorted bands are only observed in the optically darker areas of Europa, including the lineaments, and may represent evaporite deposits formed by water, rich in dissolved salts, reaching the surface from a water-rich layer underlying an ice crust.

Comparative serum estradiol profiles from a new once-a-week transdermal estradiol patch and a twice-a-week transdermal estradiol patch.

Two identical open-label, randomized crossover studies were conducted to compare serum estradiol profiles from the new 12.5- and 25-cm2 once-a-week adhesive patches with those from the 10- and 20-cm2 commercially available twice-a-week Estraderm patches when applied as directed during a 1-week patch-wear period. Both studies were conducted in healthy postmenopausal women; serum estradiol levels were determined by gas chromatography/mass spectroscopy (GC/MS). Although both sizes of both patch treatments produced mean serum estradiol levels in the therapeutic range, the once-a-week patch provided more constant mean levels, avoiding large peak-to-trough fluctuations. As expected, the differences in mean serum estradiol concentrations between the two patch treatments occurred during the second application of the twice-a-week patch. Based on these results, the once-a-week drug in adhesive patch appears to be an acceptable means of hormone replacement therapy.

Drug release rates from four sizes of a new transdermal nitroglycerin adhesive patch.

This study was conducted to determine the amount of nitroglycerin released from transdermal nitroglycerin patches of four different sizes: 3.3 cm2, 6.7 cm2, 13.3 cm2, and 20 cm2. Thirty healthy men received a single 24-hour application of each patch size according to a randomized, open-label, four-period crossover design. A 24-hour interval separated each treatment period. The total amount of nitroglycerin released by the four patches was proportional to size. All four patch sizes released nitroglycerin at a comparable rate. The mean overall 24-hour release rate of 0.76 mg/cm2 was similar to the release rate of 0.75 mg/cm2/24 hr observed in a previous study. Adverse experiences common to nitroglycerin administration were reported for all patch sizes, with headache, light-headedness, and nausea reported most frequently.

Performance of a new transdermal nitroglycerin adhesive patch formulation.

This two-period crossover study in 24 healthy men compared the transdermal absorption of nitroglycerin from a new 20-cm2 nitroglycerin adhesive transdermal patch applied for a single 24-hour period (q24hr) with that from one inch of 2% nitroglycerin ointment applied over a 50-cm2 area every eight hours (q8hr) during a single 24-hour period. The observed differences in pharmacokinetic parameters were expected, based on product design (q24hr vs q8hr) and surface area (20 cm2 vs 50 cm2); however, when corrected for surface area, the mean plasma AUC ratios indicated that the patch delivered about 1.5 times more drug than the ointment. The patch delivery of nitroglycerin was confirmed by patch residual results, which indicated nitroglycerin was released at a rate of 0.75 mg/cm2/24 hrs. The patch exhibited good skin adhesion throughout the 24-hour application period.

Improved comfort and patient acceptance in a novel transdermal nitroglycerin delivery system.

Sixty-three angina patients were recruited to participate in a two-week, randomized, open-label, crossover, multicenter trial to compare patient acceptance of two transdermal nitroglycerin delivery systems, Minitran and Transderm-Nitro (TDN). Patients were enrolled if they had stable angina and had been on a stabilized dose (5, 10, or 15 mg/24 hr) of Nitro-Dur II (ND II) for at least one month before entering the study. Patients with a bias against TDN or with any of the contraindications for transdermal nitroglycerin therapy were excluded. During the two consecutive one-week treatment periods, the patients received their prestudy dose regimen of Minitran and TDN in random order. Patients completed daily diaries, weekly questionnaires, and poststudy patient preference evaluation forms. Of the 63 patients who completed the study, 70% preferred Minitran overall (P less than or equal to 0.001), 24% preferred TDN, and 6% had no overall preference.

Improved skin adherence and patient acceptance in a new transdermal nitroglycerin delivery system.

Sixty-five patients with angina pectoris participated in a two-week, randomized, crossover, open-label, multicenter trial to compare patient preferences between two transdermal nitroglycerin delivery systems: Minitran and Nitro-Dur II (ND II). Patients were enrolled if they had stable angina pectoris and had been on a stabilized dose (5, 10, or 15 mg/24 hr) of Transderm-Nitro (TDN) for at least one month before entering the study. Patients with a bias against ND II or with any of the contraindications for transdermal nitroglycerin therapy were excluded. During the first one-week treatment period, the patients received their prestudy dose regimen of either Minitran or ND II. During the second week, the patients were crossed over to the transdermal delivery system that they had not received in the first week. Patients completed daily diaries, weekly questionnaires, and poststudy patient preference evaluation forms. Two patients, one in each treatment group, withdrew from the study because of increased angina, which was probably not related to the use of transdermal nitroglycerin. Fifty-seven percent of the patients preferred Minitran overall (P less than or equal to 0.05), 27% preferred ND II, and 16% had no overall preference.